Cangkuang village is a small knot of brick houses and muddy lanes, half an hour’s drive out of Bandung, the capital of Indonesia’s West Java province. Located on the banks of the Citarum River, the smell of cooking food mixes with something more pungent wafting up from the nearby muddy flow.

On a recent visit, locals were keen to talk about the impact of the river on their lives. Down a narrow laneway, villager Bousana pointed to a mark on the outside brick wall of a house. The line, which was well above her head, showed just how high the Citarum rises when it floods.

‘If it rains all day the water will come up to this level – this happened two months ago,’ she said. ‘It also flooded when there was a landslide; two neighbourhoods were affected. My house was destroyed and I had to move.’

The houses on the Citarum’s upstream are only 10 metres or so from the river’s edge. Standing on the banks, there’s an obvious problem – the riverbed is actually higher than the land on which the houses sit. The only protection comes in the form of massive dirt walls built to hold back the water. But still, villagers say floods are common and much more frequent than a decade ago.

In recent years, erosion caused by land clearing has washed sediment downstream, contributing to the riverbed’s current level. Local resident and environmentalist Sunardhi Yogantara said the land clearing, which is often illegal, is the result of more people moving into the river-basin to try to scratch out a living.

‘When people are thirsty of space to cultivate just for their subsistence. they go into the catchment area, let’s say the forest. Then to start cultivating they need to have a good economical commodity, so they have to cut down the trees to allow enough sun’s rays to grow their cultivation.’

The river is not only an inconvenience to villagers when it floods — it’s also a health hazard. The water near Cangkuang was speckled with the colours of modern-day living. Bright plastic rubbish – drink bottles, plastic bags, food containers — lined the banks. Canals filled with dark, sluggish-looking water from Bandung emptied into the mainstream. In some places, makeshift toilets, shielded from view by gaudy plastic curtains, jutted out and emptied directly into the flow.

Sunardhi Yogantara, who belongs to a group called Care for the Environment, said we were lucky our visit coincided with the rainy season when the water level is high; during the dry the river is even more ‘colourful’.

But even more worrying for locals is the pollution we couldn’t see. On this stretch of the Citarum, textile and electronics factories as well as slaughterhouses have waterfront views, as does a massive coal-fired power station. Of the 1500 factories upstream, only 20 per cent have a comprehensive water management system.

When I spoke with Lusia Boer, the Director of Environmental Pollution Control at the West Java Environmental Management Agency, she could easily rattle off the Citarum’s problems, but preferred to talk in terms of risk. She said that while domestic waste comes in the biggest quantities, pollution from factories poses the greatest threat to life along the river.

‘Industrial waste is more toxic since it contains metals and other substance,’ she told me at her office in Bandung. ‘Factories surrounding farming areas reduce the productivity of the land. Fisheries are also affected – if there is less oxygen in the water, then the productivity of the fish will also be lower.’